<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <h1>我是a页面</h1>
    <button class="btn1">红色</button>
    <button class="btn2">蓝色</button>
    <script>
        let btn1 = document.querySelector(".btn1");
        let btn2 = document.querySelector(".btn2");

        btn1.onclick = function () {
            window.location.href = "./b.html?type=1";
        }
        btn2.onclick = function () {
            window.location.href = "./b.html?type=2";
        }



    </script>
</body>

</html>